Screw-jack.



I. E. HINDMAN.

scREw nox, APPLICATION FILED FEB. 26' I9I6.

Patented m5251917.,

4 SHEETS-SHEET 2-l I n l I. x l

WITNESSES Lf.v HIND'MAN,

scnew JACK', v 1 Armcmon mtb 'fzzm 191.6. ,Patented May 29,1917. Y 4 sains-super a.

la u N @s w H WST/Gm.

scREw'JAcK. APFLICATIDII FILED FEB. 26. l9l6.

Patented May. 29,- 1917.

4 sains-suur 4.

.wmf

WITNESBES UNITED STATES PATENT OFFICE.

ISAIAH E. IE*IIII'Dl/IAIYI',,0F OAKMONT, PENNSYLVANIA, ASSIGNOR T0 THE DUFF MANU- ACTURING COMPANY, F PITTSBURGH, PENNSYLVANIA, A CORPORATION OF TENNSYLVANIA.

SCREW-JACK.

Application filed February 26,. 1916. serial Np. avisas. A i

To all 'whom 'it way Concern:

Be it known that I, Imran' 1*). I-liNmiAx, a eitinen of the nitcd States, residing at Oakinilnt, in ythe count;Y of Allegheny and State of le1msyl\;ania have invented a new and;neet'vul. 'Improvement- .in Soeur-Jacks, otI whichthe followii'ig is a full, clear, and exact' description, 'reference being had to the accompanying drawings, forming part of this Uspeciieation, in which 4.ligure `l is a side elevation partially insection on, the line I-I o'l Fig'. Li.

Fig. 2, is a vertical section on the line II-II of Fig. 3.`

, Fig. 3 is a sectional plan view on the line III-III of Fig. l.

Fig. #i is a. similar View on the line IV-IV of F ig. Fig. 5 is Va front View with a portion in 20, section approximately on the line V-V of gig. iS :i detail View of the shaft of the lowering inechanisn'i.

Fig. 7 is ail-end 'View thereof.

Fig. 8 is a detail seetiolnil View, on an enlarged s eale, of a portion ot' the mechanism shown in see-tion in Fig.

o, `showing' the parts in position when` the screw jack is' moving downwardlyonder the action of thc load.y A, v

Fig. 9 is a` View lSimilar to .l.1"ig. oly a port-ionthereofshowing the position olf the parte` when the j'aek sei-ew is being`- lowered by they lowering meclilanfisln. I lt) is a detail perspective View of the of4 the Shafts," 'lofi the loweringI nieizliaand the lolzli-actuating mechanism. Fig. lllis a detail. lfiectional View olf a portioniol' the looking` nibchanism. and

lig. 12 i9 an end View ol theerank shaft- .sliowing theelntifh ,member for actuating "the loeli releaaing shaft. andthe shalt ol" the h nvering mechanism. i

Thiel intention, relatesy to anim|n"o\'ement in Self .lowering soi-ew jacks which can safely be lowered at. va high rale, of speed by neansol* the load and.y at. the same time, eontrolthe rate ot speed o'l' the i'lownward movement the reol. Olie rof-.t'he objet-teA ot' my invention in to pxgovide a fiaelc oi this eharaeter which is glnlfrlqle and simple. ol4 eontruetion and in which-'the mechanism is arranged to be ae- Speccation of Letters Patent.

'raising a .screwint't'iposition under a load.

.Patented May 29, |917..

tuated step b v step by means ol a ratchet l i "l .lever to raise the load. Another object o'ti55 my inrention is to ljnoride loeliilig-mecha niam lor the jack. screw to prevent the downif ward movement thereof, and which locking' mechanism is so arranged'that when actuated the jurk lscrew 'in lree to be rotated under the weight'o'l the load to lower it. Jfurther object oiE in invention is to provide positive lneans enacting' with the locking mechanism to positively lower the load, if l'or an)Y reason the jack screw ahould become jammed.' Still a furthia object ol1n inren. tion is to so arrange the .locking mechanism that the jack screw can be quickly raised thereby when raising a light load, or for The preeise natureol. my invent-ion will be best'. understood b y ret'erelieeV to the aecon|pau \-ing lrawings whieh will now be described, it'l being premised, however,4 that various changea4 may bemadc in the detailei of construction and general. arrangement of. the parts without departingfrom t-heispirit and scope. o'l' my inrentionas deliiied'in the appended claims.

Referring to the aecompanyinev drawings, the reference charaeter i), (,lesignaten a base and supported within this` base is a. hollow stein 3, which, may be connected to the bas in lan) desiredV manner. (-onneeted lo .the upper portioniof the hollow stem is a bush-v ing i,4 and eonneeted to thinI bushing el 'by means olf' screw" 5 ia a n-ut t3. The screwls' 5, extend' through the hollow :steinf and the bushing 4, and are lSeated. vin openingb` in the nut. The nut (i anllsleeve l are. lixei'llyY connected to the end of' the hollow stein, and rota tahly `mounted within-the nutti is a. jack screw 7.- Connected to the jack.A serew 7 by .means ol a: ke)r visa bevel gear S, and l) is a. hood eonnmted to a top lplate 10 whieh is aupported by vmenno of" ball bearingsl lli. beta-'een the bevel gear S andl the plate 1t). Connected to 4the. .lower end' .of the hood E) is a` shell 12 which is provided with a bushing 1E, at the lower end. thereof, which is slidafbly mounted on the hollow stem 55. 14 is a spacing ring oonneeted tothe bushing il which forms a bearing for the .shell 12 and aetop for the shell bushing 13. 15in a bonnet conneetedto Vthe side of the hood, and journaled 'in this bonnet is a stub shaft 17 having a beveled pinion 18 on the end thereof, which. meshes with the bevel gear 8 for actuating the screw 7 to lift the load. The end of this shaft 17 is provided with a hexagonal portion. and mounted thereon is a ratchet wheel 19, which is heldin position in a socket 20, rotatably mounted on the en d of the shaft 17. This socket 20 is arranged to receive the usual lever for actuating the jack to lift the load. Pivotally mounted'in the lever by the plunger 22 to hold the pawl in anV elevated -position clear of the teeth.

The` pitch of the threads on the jack Screw 7 is inclined sufficiently so that the Weight of. the various parts supported by the screw will causethe screw to move to its downward position. In order to retain the parts in their elevated positions, I provide a lock which comprises a large spur gear 24 which is pinned to the large bevel gear '8. i mesheswith the spur gear 24 and is -fixedly connected to the upper end of a vertical shaft 26 rotatably mounted in the hood 9. 27 is a clutch member spiined to the shaft 26 and adapted to be positively rotated thereby, being held in its downward position by means of a compression spring 28. The lower face of this clutch member is provided withv a plurality of teeth which are adapted to engage similar teeth on th'e upper end of a Worm wheel 29, which is loosely mounted on the shaft 26. This worm wheel 29 is engaged by a worm 30 which is keyed to a sleeve 31. This sleeve 31 is rotatably mounted in a bearing 32 in -the bonnet, and rotatably mounted within this sleeve 31-is a stub shaft 32".

33a is abushing interposed between the stub shaft-32a and the sleeve 31 and is provided at one end with a flange 34. The flange 34 is secured within the hood 9, and is interposed between the worm 30 and a spur vgear wheel 35 secured' to the end of the shaft 32'. This flange 34 sup-ports' one end of the bushing 33, while the other end thereof is supported by the bearing 32 through the medium' of the sleeve 31.

Mounted within the bearing 32 is a. crank shaft 36, Iprovided with a boss 37 land a clutch projection 38, the boss37 being rotatably. mounted in the bearing 32, while the body of the crank shaft 36 is rotatably 25 is a small 'spur gear which projection 42 and a recess 42, and whichprojection is adapted to be engaged bv the clutch projection 38 on the crank shaft 36.

When raising a load,.the ratchet wheel`19 is actuated by means of the socket lever which, through the medium of the gears 18 and 8, will rotate the screw to lift the load, which will in turn actuatefthe gears' 24 and 25, together with the shaft 26 and the clutch member 27, the latter being free to rotate in one direction, namely, the direction for lifting the load, but is prevented from moving in the reverse direction by meansof the engagement of theworm wheel with the worm.

When it is desired to lower the jack, the crank 41 is rotated in the direction .indicated by thearrowin Fi 8, and through the connection between t e projections 38 and 42 will rotate the sleeve v31, together to move downwardly.

In jacks of this character, it is very desir.-

able to provide means to positively rotate the jack screw to'lower it, as I have discov;

ered that the jack screw is liable to become `jammed at times, and have4 therefore devised means co-acting with the lockin'g mechanism to simultaneously rotate the lock, and at the same time positively actuate the screw.

The positive lowering mechanism comprises a spur gear 43 connected to the end of a shaft 44,. j-ournaled inbearings in the bonnet 15. This spur ear 43 meshes with the spur gear 35 on the end of the shaft 32 so that the shaft 44 will be positively rotated when the stu'b shaft 42*I is rotated, as herej inafter described.

45 is a skew gear mounted on the shaft 44 which meshes with a`skew gear 46 connected to the shaft 17.. The end of the stub shaft 32ll is provided with' a projection 47 which is also adapted to be engaged by .the clutch projection 38 on the end of the crank shaft 36, as illustrated in Fig. 9.-

Assuming that the jack screw has been-.elevated and the various parts are in the position shown in Figs. 5 and 8, it being desir,- able to lower the jack screw, thel crank 41 will' be rotated counter-clockwise, as indi-4 cated by the arrow in Fig. 8, which will rotate the sleeve 31 and permit the jack screw to move downwardly, as hereinbefore described.

If, for any reason, the jack screw should ment thereof, mechanism for rotating the screw in the reverse direction, and means to actuate the locking mechanism and last mentioned Screw actuating mechanism to unlock the screw and permit thescrew and nut to move relative to each other in the reverse direction; substantially as described.

9. 'A screw-j ack having ratchet mechanism for elevating the screw, a rotary lock for said'screw, a one-way clutch interposed between said lock and the screw and adapted to. rotate therewith, gearing for rotating the screw in the reverse direction, and means for rotating said screw and the lock to lower the screw; substantially as described.

10. A jack having a lifting screw, gearing for raising the screw, a second set of gearing for lowering the screw and to prevent the screw from rotating under the action of the load, and a clutch connection between said sets of gearings and arranged to per- I. mit the gearing for lifting the screw to be actuated without affecting the gearing forl lowering the screw, substantially as described.

l 11. A jack having a lifting screw, av lock comprising a worm and worm wheel connected tothe screw and arranged to prevent it from moving downward, mechanlsrn for elevating the screw, and mechanism for rotating the worm and worm wheel to permit the screw' to move downward, said mecha' nism alsol being arranged tocause the rais ing mechanism to move in the reverse direc'- tion, substantiall7 as described.

12. A jack having a lifting screw, gearing`V for actuating said screw, a lock comprising a worm and wormwheel for preventing' said screw from moving downward, a clutchv between said lock and the screw arranged, to permit the screw to be elevated but to pre? f vent it from being lowered, and mechanism for simultaneously rotating the lock and the gear wheel inthe reverse direction'. tolower the screw, substantially as described..`

In testimony whereof, I have hereunto'set my hand.

l .,ISAIAH E. HINDMAN. Witness:

GEO. A. .Yo-ciao. l 

